1. Field of the Invention
The present invention relates to an input module with capacitance sensors, a method for manufacturing the input module and a method for constructing an algorithm for processing an input corresponding to force applied by a user's finger to the input module with the capacitance sensors. More particularly, the invention relates to an input module having a top plate, which can be deformed by force applied by a user's finger and has pitches formed thereon, and capacitance varied according to the magnitude of force applied by the user's finger, a method for manufacturing the input module and a method for constructing an algorithm that determines a specific force vector based on the center point of the top plate of the input module when force is applied to the input module and moves an input module cursor pixel by pixel using the specific force vector.
2. Background of the Related Art
There are various kinds of force measurement sensors including a contact resistance sensor that measures a resistance variation caused by force. This contact resistance sensor has a complicated structure and requires high cost and technique to bond a metal resistor included therein.
Accordingly, there is a demand for development of a capacitance sensor using a capacitance variation as a force measurement sensor. The capacitance sensor has capacitance from the relation between a user's finger and a metal included in the sensor and thus, when the user touches the capacitance sensor, the capacitance sensor senses the touch.
However, although the capacitance sensor can sense the touch because capacitance is rapidly formed when the capacitance sensor is touched, it is difficult for the capacitance sensor to correctly measure force when the capacitance sensor is touched and then the force is applied thereto by the user's finger. Accordingly, development of a capacitance sensor capable of sensing touch to provide an on/off function and correctly measuring force is demanded.
Furthermore, a technique of forming the capacitance sensor in an input module that moves a curser on a display, measuring force applied by a user's finger to a top plate of the input module and moving the cursor without moving the input module has been studied. However, the input module including the capacitance sensor also has a complicated structure and low production yield, and thus it is difficult to reduce the size of the input module.
Accordingly, a method for measuring force applied to the top plate of the input module using the capacitance sensor included in the input module to move the cursor is required. While the input module including the capacitance sensor has a simple structure, the input module cannot correctly measure force applied thereto because a capacitance variation caused by the force is small, and thus the input module cannot naturally move the cursor to a desired point. Accordingly, an input module with a capacitance sensor capable of measuring force with accuracy and allowing a user to freely move the cursor to a desired point and a method for manufacturing the input module are demanded.
Furthermore, an input module having a force measurement sensor requires an algorithm of moving a cursor on a monitor when a user applies force to a predetermined portion of the top plate of the input module. To construct this algorithm, it is required to obtain a specific force vector with respect to a portion to which specific force is applied in coordinates having the origin on the top plate of the input module. Accordingly, a method of setting the coordinates on the top plate of the input module and determining the specific force vector is required.
Moreover, it is required to analyze the motion of the cursor on a pixel-based display screen according to the specific force vector after the specific force vector with respect to the force applied to the input module is determined. Accordingly, a method of determining a cursor moving direction using the angle of the specific force vector and a method of smoothly moving the cursor on the display screen pixel by pixel to a desired direction are needed.